Dave,
As the Europa US Distributor I have registered a number of Europas and
have talked extensively with the FAA regarding registration of both
wings.
It is a piece of cake, and the EAA has an excellent series of downloads
on how to fill out the forms.
Notes:
Register the aircraft as an airplane! Not a motorglider.
Your DAR should by now have direction on the limitations for your
fly-off with both wings.
They are in a nutshell: Fly with short wings the 40 hours (Clear
your Stage 1). Then fly an additional 5-10 hours depending on your DAR
to establish the characteristics with the long wings (when adding glider
wings later, your initial airworthyness restrictions on where to fly are
considered and may be re-imposed).
You do not need to dual register the aircraft, that is the pilot rating.
I talked with the FAA senior trainer for DARs regarding the Europa dual
wing and pilot registration problems. If your DAR has a problem, he can
call Brad Outlaw or Les Sargent at the FAA (Brad is the senior trainer
for QC) and Brad will give him the straight skinny.
I am attaching the Motorglider Pilot Handbook for you to download and
print. All the numbers are there.
I have suggested an operational limitation for the airbrake opening for
one pilot due to his experience as his airbrakes tend to flutter just as
you crack open the airbrakes above 100KIAS. Once deployed they are
smooth. As a result of being harder to deploy above that speed and
personally, the resultant pitch down associated with them at speed and
the force to hold them open is a nuisance, so we limited his aircraft to
near normal flap lowering speeds of 85 KIAS because for him they are
mainly used in the pattern rather than high speed descent. The motor
glider is deceptively fast. When built light and at low altitude (1500
feet) and 75% power on a Rotax 912S you will cruise near 110-115 KIAS.
One updraft and a little push over and you are over 120 in a heartbeat.
As for marking, the FAA was amenable to dual markings. This presents a
problem for EFIS equipped aircraft as the devices show only one set of
speeds. Perhaps your DAR will allow a placard next to the EFIS if so
equipped.
In my experience with the three motor gliders I have helped construct,
the CG shifts forward about .75 to 1.0 inch with the glider wings. Yes,
you must do another weight and balance. Typical weight increase is 100
pounds. (It was more of a reason to diet.)
CG will determine if you achieve a stall or if it is nose heavy, where
full aft stick limit is achieved. CG limits are the same for both wings
and the aircraft flies best, in my opinion, with the long wings at about
60 inches empty. I have only gotten down to 55 KIAS full aft stick due
to forward CG on the aircraft tested (59.25 inch).
I am posting, at my own dread, my rant on Vne to another builder.
My background is a military fighter pilot and a Functional Test Pilot
(the guy who gets stuck flying the aircraft after a complete teardown or
problems with aircraft handling or the stability and control systems)
and as such have some experience in taking aircraft routinely to their
design limits of airspeed and G to assure proper operational safety. I
am also an Aeronautical Engineer (Parks '72) and an avid EAAer. So here
is my rant edited for children and sensitive adults:
Airbrake extension is Vne but I find 85 knots to be most comfortable as
they can vibrate on opening and closing above 100KIAS.
Vne 129 KIAS
Vlg is 83 KIAS (Gear and Flaps came down together right!)
No idea what is maneuvering above 1370. You must pull max G and achieve
the stall simultaneously to find the value to determine Vmanuever.
RE G limit
You must lower your G proportionately above 1370 lbs due to
wing/airframe stress.
I interpolated some a long time ago and made a placard in excel for
someone. Hope the cut and paste is readable.
STRUCTURAL LIMIT: +3.8g / -1.9g at 1370lbs.
+3.5g / -1.5g at
1450 lbs.
+3.3g/-1.3 at
1550 lbs.
The landing gear has only been drop tested to 1370. You should drop
your aircraft 12 inches at the max landing weight you are redesigning to
for verification.
Added Note: The trigear legs move a lot at 1550 pounds. It will get
your attention. The monowheel squats even more.
Yes I have flown the aircraft over gross, but very gently and got away
with it. I don't do it on a routine basis and don't recommend it.
Although someone has flown their personal aircraft beyond the limits,
that doesn't mean yours will do the same. Every builder has different
standards and conditions on building his aircraft. That's why
production aircraft have quality control procedures but, we kit builders
in the US are not blessed or affected by them, only our personal QC.
The Glider POH is attached but is not PFA approved or edited as of this
printing. The PFA has still not certified the wings because of the the
PFA getting to it, but all the testing has been completed and
adjustments made years ago. John and Roger at the factory are pushing
them as hard as they can.
As for Vne. It is the value determined by the engineers and test pilots
together.
It is generally an indicated airspeed or a mach number (some of the new
all glass biz jets display the limit on the TAS display but it is really
a mach limit).
Added Note: Mach varies primarily with temperature, therefore it is
altitude dependent. Mach and TAS are proportional in that .8 Mach is
480 KTAS at F-4 cruise altitudes to within a couple of knots. See the
note on your E6B computer and test it yourself. Wing design (camber and
sweep) determine Mach crit. The aircraft shape and planform determine
the effects of Mach crit.
Vne is determined by the design limit, the Q limit (dynamic pressure)
and the structural anomalies such as flutter, wing divergence,
windscreen implosion, tail plane effectiveness due to critical mach,
etc. The value must be read by the pilot with basic flight instruments
provided by the manufacturer. It is also affected by the gust factor
and other government imposed guidelines on designers. Allowances are
made, and some safety factors are involved but not printed for public
use. Vne has never been a TAS limit in any design class or aircraft I
have flown. The airplane only feels indicated airspeed (dynamic
pressure) and mach effects period.
The T-38 is limited by the Q on the windscreen,
The T-33 by the mach crit.
The F-4 by the longitudinal stability and radome Q limit (heat and
pressure)
You guys are too much into details on the internet. All you guys need
to know is it is the limit that is imposed, by one of the factors deemed
important.
Bottom line: Limits are limits. Boldly going beyond them is to be
avoided. Changing the operational limits of an aircraft must go back to
the manufacturer. By the way Mr. Mac's engineers built the F-4 to meet
a certain spec and said, if you need more G, it will cost you!
There are old pilots and bold pilots, but no old bold pilots....I have
been to their funerals. Build a Europa light and by the book and the
aircraft will give you what we have found to be a delightful sport
aircraft. If you must change your aircraft, seek paid professional help
willing to stand by their recommendations. Kit manufacturers which open
up actual test results expose themselves to assumptions that a novice
may make in a modification to the construction of his aircraft or its
operation.
All manufacturers learn and improve their products through field
experience. That is why I respect the Europa Club and their approach to
aircraft mods. The UK owners are limited by PFA guidelines, but work
within the system to make the product better. And all the manufacturers
listen. We in the states have more latitude and it is forums like this
where we can find out what has worked and what was done to make it work.
Sorry for the rant. Keep asking questions and doing the research.
Those of us who can help on these forums generally do. I lost two hours
of shop time putting together emails such as this, and I can't afford to
do it as often as I would like to weigh in. Looks like I will be
working late tonight.
I hope this has helped and please call if you get stuck on registration.
Off my soapbox now,
Bud Yerly
Custom Flight
813 653 4989
www.customflightcreations.com<http://www.customflightcreations.com/>
----- Original Message -----
From: David DeFord<mailto:davedeford@comcast.net>
To: europa-list@matronics.com<mailto:europa-list@matronics.com>
Sent: Tuesday, September 25, 2007 9:59 PM
Subject: Europa-List: motorglider V-speeds and registration
<davedeford@comcast.net<mailto:davedeford@comcast.net>>
We are just about ready for paint on our motorglider wings, and we
have a
few questions for other motorglider operators.
1. What are the expected stall speeds with the long wings, what are
Vno and
Va, and what is the limiting speed for airbrake extension (if any)?
2. How have people marked their airspeed indicators to show values for
both
short wings and long wings? Two concentric sets of arcs?
3. What are the C.G. limits with long wins?
4. Any hints for convincing the FAA to grant registration in two
categories
(ASEL and self-launch glider), depending on which wings are installed?
We
have been flying with the short wings for 6 years, so a change from
the
existing category and operating limitations will be required.
5. Keeping potential controversy for last, how does Vne vary with
altitude?
(The Diamond Extreme in which Terry and I recently got our self-launch
glider ratings has a placard which derates Vne from the marked value
at 6500
feet by exactly the same ratios as shown in the table for the
Pipistrel
Sinus, referenced in the article recently posted by Richard Pottorff.)
Thanks.
Dave DeFord
N135TD
http://www.matronics.com/Navigator?Europa-List<http://www.matronics.com/N
avigator?Europa-List>
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